So-called complaint of general malaise of gastrointestinal tract, such as heartburn, abdominal distension feeling, anorexia, unpleasant feeling on upper abdomen, nausea, vomiting, abdominalgia, etc., develop as the symptoms of diseases such as acute and chronic gastritis, stomach and duodenum ulcer, gastroneurosis, gastroptosis, etc., and the major underlying cause is the decrease in gastric emptying potency via the gastric hypanakinesis.
So as to improve gastric hypanakinesis, use has conventionally been made of 4-amino-5-chloro-N-[(2-diethylamino)ethyl]-2-methoxybenzamide [generic name; metoclopramide: see Merck Index, 11 ed., 6063(1989)], but it has been known that the agent has side effects including damage to the on extrapyramidal system or side effects on central nervous system.
Research works has been made on the pharmacological properties of a variety of substituted benzamide derivatives recently synthesized. Consequently, reports have been proposed of compounds capable of improving gastric hypanakinesis without causing the damages and side effects described above.
Known examples thereof include 4-amino-5-chloro-N-[1-[3-(4-fluorophenoxy)propyl]-3-methoxy-4-piperidinyl] -2-methoxybenzamide (generic name; cisapride: Japanese Patent Laid-open No. Sho 58-90552) and (endo)-4-amino-5-chloro-2-methoxy-N-[1-azabicyclo-(3.3.1)-non-4-yl]-benzam ide hydrochloride (BRL-24924: Japanese Patent Laid-open No. Sho 62-270583).
Alternatively, it has been reported that a heterocyclic carboxylate derivative synthesized as an antagonist of the 5-HT.sub.3 (serotonin 3) receptor is effective for the improvement of gastrointestinal disorders.
Known examples thereof include (endo)-8-methyl-8-azabicyclo[3.2.11octan-3-yl indole-3-carboxylate hydrochloride (ICS205-930: Japanese Patent Laid-open No. Hei 2-237920) and (endo)-N-[8-aza-8-methylbicyclo[3.2.11octan-3-yl]-l-methylquinolin-4-one-3 -carboxamide (GB2236751A).
However, expectation has been toward the development of a novel compound capable of further improving gastric hypanakinesis.